Lifting-bridge.



'PatentedTeb. I8, 1902.

km. WADDELL', .LIFTING BRIDGE.

(Application filed Oct. 1, 1501.)

' 3 sheets--sheet I.

(Np Model.)

THE Noams PETERS 20. mom-LING" wAsmMuToN, D. c.

Patented Feb. 18, 1902;

In. wAooELL. LIFTING BRIDGE.

(Application filed on. 1.1901.

1 3 Sheets$haai 2.

(No Model.)

n4: nonms FETERS A0 PHOYO-LITNOH WASl-HNGTON, 5. (:4

-No. 693,467. Patented Feb. 18', I902.

m. WADDELL.

LIFTING BRIDGE.

v (Application filed Oct, 1, 1901,) (N muu l.) Y 3 Shuts-Sheet 3.-

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1 "UNITED STATES PATENT OFFICEI MONTGOMERY WADDELL, OF NElV YORK, N. Y.

LlFTING-BRIDGE.

srnornrcarron forming part of Letters Patent No. 693,467, dated February18, 19.02. I

I l Application filed October 1,1901. Serial No. 77,181 (No model.) I

T0 ctZZ whom it may concern:

Be it known that I, MONTGOMERY WAD- DELL, a subject of the King of GreatBritain,

residing in the city, county, and State of New York, have invented acertain new and useful Improvement in Lifting- Bridges, of which thefollowing is a specification.

An ideal lifting or bascule bridge should present the followingconditions: The tilting section of the bridge should be balanced so asto require a minimum of effort to move in all positions of the bridge,when fully raised the whole span width should be clear for passage ofvessels without waste of room on the piers, and the entire bridge andits counterweight andoperating means should preferably remain alwaysabove ground, so as to avoid pits or cuttings in the abutments or piers.

It is the main object of my present invention to provide a lifting orbascule bridge presenting all the above advantages and at the same timeto so mount and guide the counterweightthat it may be made as lightaspossible, thus reducing the total weight of the moving structure, andthereby reducing its inertia and its first cost.

'My invention is illustrated in the accompanying drawings, wherein- VFigure 1 is a diagram illustrating the mathematical principles involvedin my device for mounting and guiding the counterweight. Fig. 2 shows aform of bridge in which the exterior directing or limiting means isrigid. Fig. 3 shows a form of bridge wherein a flexible exteriordirecting means is employed. Fig. 4 shows a deck-bridge of the sameclass; and Figs. 5 and 6 are a top View and an end view, partly insection, respectively, of the preferred novel means for applying powerto open the bridge.

7 In Fig. 1 the lower chord of a bridge is indicated at 1 in ahalf-raised position. The counterweightis shown at 2. A guide 3 is fixedto the bridge, so as to turn with it around the center of motion, whichmay be a pivot, as shown at 4. This guide carries the counterweight 2,which may be mounted thereon in any desired manner so long as theprecise path of the counterweight is determined by said guide.

It is one of the fundamental principles of body 2.

my invention that a guide '3Yis employed to lead the weight 2toward'thecenter of movement 4 of the bridge when said bridge tipsupward and that this motion toward the cen' ter of movement is furtherdetermined byan exterior directing means, which may be arigid arm or, aspreferred by me, a flexible cable. Where a cable is used, one end isanchored,

as at 5, to a point fixed upon the shore, the

other end being fixed to the counterweight. The cable passes over apulley 6, preferably fi xed upon the bridge itself. This is the formintended to be represented in diagram in Fig. 1. In this form of bridgethe counterweight acts in a dual capacity. It forms a movablepulleycounterweight, since its supportingcable passes over a pulley movablewith the inshore end of the bridge. At the same time instead ofdescending freely in a vertical line it is supported upon a guide 3,also on the inshore end of the bridge,-and by pressure upon said guideit acts as a direct counterweight.

If we assume the center of gravity of the bridge itself independently ofthe counter-f weight to be at a, the weight of the bridge beingrepresented by the line W, and if the, t

vertical line through the center of movement be be, then ac is'thelever-arm of the downward or, positive turningmomentexerted by theweight W of the bridge. Now this turning moment is opposed by the twoefforts into which the gravity of the counterweight 2 may be analyzed.The indirect elfortis that which is opposed by a stress in the cable 7.The direct effort is the simple weight w of the direction of this lastor direct effort. Then if the line df be a. continuation of thedirection Supposethe vertical line ole to represent in length anddirection the quantity and.

assumed by the cable 7 near the weight 2 and a perpendicular ef is drawnto a line dg tangent to the guideway 3 at the point occu-' pied by theweight 2 the line df will represent by its length the stress in thecable 7. By drawing a-perpendicular to theinshore direction of the cable7 from the point 4 the lever-arm 4 is obtained, which multiplied by thestress df (called 8) gives the turning moment of said stress tending totilt the bridge. The line 61) is the lever-arm of the direct efiortexerted bythe body 2, and the moment is found by multiplying the weightof the body 2 by the arm 61). Now in order to avoid all resistance tomovement of the bridge either way directly due to its weight thefollowing equation should be true:

. Where IV is the weight of the bridge, to is the ance the counterweightcan be made quite small relatively, and even in such a case as thatshown in Fig. 4:, for example, this weight may be made less than that ofthe bridge.

Inspection of Fig. 1 will show that as the tangent (lg to the guideapproaches the ver-' tical (which it does when the bridge closes) theperpendicular cg will cut the line dffarther and farther from d, andthis increase will take place faster than the decrease in the lever-armeh of the direct effort. Thus is secured an increased indirect effort,giving an increased total negative turning moment to correspond andcounterbalance the increasing positive moment of the bridge as itapproaches the horizontal.

In the arrangement indicated in Fig. 3 a counterweight 1.32 times theweight of the bridge will snffice.

It is of course to be understood that while a perfect neutral balance isdesirable over a large part of the total opening and closing movementscircumstances will usually make it desirable to depart from thiscondition at certain points in the travel of the bridge. For instance,it may be desired to balance the bridge so that it has aslight closingor downward tendency near the entirely open position. This causes agentle stop, avoiding shock as the opening bridge comes to rest andgiving a ready return when the bridge is to be closed again. On theother hand, it will often be well to produce the same effect in or nearthe closing position, so that there is a certain tendency of the bridgeto open when closed. Appropriate locking devices of any age 9. On theend of this arm is the counterweight 2, running upon a guide 3 ofsuitable form. As will be seen from the dotted lines in Fig.

2, the counterweight is made to run of this device are explainedhereinafter;

down along the guide 3 to a position near the center of movementa of thebridge. The contrary movement occurs on closing the bridge. In, thisform of bridge, as in the others, the span is clear from pier to pierand all parts of the bridge and its accessories are above the pier-head,as shown. This form of my invention may be used with advantage indeck-bridges.

Fig. 3 exhibits the very simple form to which a practical bascule-bridgeis reducible when made in accordance with my invention. Here a cable 7is used, running over the pulley 6, while the counterweight attached tothe end of said cable runs in a guide 3 of very simple curved form. Inthe form actually shown this curve is the arc of a circle. As shown indottedlines, when the bridge is open the counterweight is brought nearto the center of movement 4:. In this figure Ihave shown a preferredmeans for applying power in opening the bridge. This consists in anoperating-arm 10, pivoted to a fixed anchorage 1.1 and carrying at itsmovable extremity gearing 12, adapted to work in a rack 13, convenientlyplaced upon the bridge. The details Inspection of the parts of Fig. 3shown in dotted lines will indicate the relative movements of the bridgeand its operating-arm.

In Fig. 4 is shown a deck-bridge provided with a preferred form of myinvention wherein a counterweight actually lighter than the bridgestructure may be used. In this form two movable pulleys ('3 and 6 areused, and the weight 2 runs in a substantially straight guideway. Theanchorage of the cable 7 is accomplished through the operating-arm 10,to the extremity of which it is fixed. The location of the pulley 6 issuch that before the gearing 12 comes opposite the pulley the cable 7acts to aid in tilting up of the bridge, and when said gearing advancesmaterially beyond the pulley 6 said cable tends to retard movement ofthe bridge. These effects can be made to correspond, respectively, to atime before and after the center of gravity reaches a vertical throughthe center of movement 4:- The gearing 12 is made to turn in the rack 13for operating the bridge by means of any appropriate motor either on thebridge or elsewhere; but I prefer to use a motorstanding upon or nearthe pier, as shown at 14:. The means for transmitting power from such amotor to the gearing 13 are illustrated in detail in Figs. 5 and 6. Thearm 10, pivoted at 11, carries a primary gear 15, which drives the shaft16 by any means such, for instance, as the bevel-gears 17 and 18. Thegear 15 may be driven in any desired wayas, for instance, by the pinion19 on the shaft of an electric or other motor 14. The shaft 16 turns insuitably-placed bearings 21 and extends to the outer end of the arm 10,where it carries a bevel-gear 22, meshing with a like gear 23 to drive ashaft 24:, carrying a pinion 12. This pinion meshes with the rack 13,carried This isnecessary'toallow free turning'of the wheels 29at alltimes. Thepinin12should- 'haveteeth deep enough to permit of move-; 5

" withoutcausingdisengagement; Itwillbe un-r 7 in any suitable manner onthe bridge. I prefer to confine the pinion 12 by some such Here thec'hannel-bar carries the rack '13 on its upperv means as shown in Fig.6:

side, while tracks 26' and 27 run along inside the bar 25 on both sides..A frame 28 car- .ries the outer bearing of the pinion 12 and i alsocarries the pulleys 29, adapted to moon oneIor the other of the tracks26 27 In Fig. 6

is shown thesmallcleara'nce' maintainedbetween one or the other trackand these wheels.

mentofthe pulleys 28: from a track to track derstood that the wheels 29will run upon o'ne or the othe'rof the tracks provided, according Y towhether a pull or a, push is exerted in the armlO. The frame or carriage28 is.-pivoted upon the hub 30, carried bythe extremity of the arm10,1:0 accommodate the-varying angle I between these two incident 'tomovement of the bridge.

- Avar-iety of operating] means maybe em ployed with my improved;bridgeand many other modificationsmay'be made in theforms herein specifiedwithout departing from the spirit of myinvention. Iam therefore not tobe understood as limiting-myself to the precise details herein shown anddescribed.

WhatI claim isv 1. In a bascule-bridge,a coun terw'eight and a guidewayfor the same fixed on said bridge and extending upward from near thecenter of movement of said bridge when the same is closed.

2. In abascule-bridge, acounterweight, a guideway for said counterweightonsaid bridge extending upward from near the center of movement ofsaid'bridg'e when thesame is closed and means attached outside of saidbridge for directing the movement of said counterweight upon said guide.

3. In a bascule-bridge, a counterweight, a

. guideway therefor on the bridge and a flexible cable anchored'ontsideof the bridge for limiting the movement of'said counterweight upon saidguide. I Y

4:- In a bascule-bridge, a counterweight, means fixed to said bridge forguiding said ingto support said connterweight. n r a I I 5. Inabascule-bridge, .a counterweight, a guideway therefor fixed to'thebridge, aflexi counterweight, and a flexible cable-cooperatj v 55.blecableattached" tosaidcounterweightand 1 anchorcd'outside'of' thebridge and a-pull'ey counterweight, and 'a'guideway fixed-to said on thebridgexover which said cable passes. 6. In a lbascule-cbridge, a1m0vable+pulley i .60

bridgefor'g-uidingsaid counterweight.

7 In a basculeebridge, a'fcounterweight, a

flexible cable attache'dto saidcounterweight' at onevend and anchoredattheotherlendand 1 3 to thebridge making a varying angle withw f saidcableduringimovementofthebridge;- I 8. In means for raisingbas'cule-bridges, ah] anchorage, a connectingdevice rotatably fixedthereto for transmitting the operating a guiding means forsaidcounterweight fixed strain and power -t'ransmitting .means. an

tached to the end of said'connecting device directlyj tending tomakesaid end travel along'a predetermined path on said bridge. 9. In ameans for raising bascule-bridges,

gear and means anchored pivotally outside of said bridge carrying saidgear.

. 10. In a means for raising bascule-bridges,

a rack on the bridge, a traveling gear-wheel engaging therewith, apivoted operating-arm carrying said gear-wheel, a motor outside of saidbridge and transmitting means between said motor and gear-wheel carriedby said operating-arm.

11. In a bascule-bridge, a counterweight,

va guideway therefor, two pulleys onsaid bridge and a flexible cablepassing over said pulleys and attachedto said counterweight and to ananchorage outside of said bridge at its two ends respectively,

arackon' the, bridge, a traveling gear-wheel engaging therewith, a motorforturning said 12. Ina bascule-bridge,a counterweight,

a guideway therefor, two pulleys on-the bridge, a pivoted operating-armand a flexiother end to said operating-arm..

MONTGOMERY VVADDELL. Witnesses: r

ABRAHAM GOLDSHEAR, H. S. MAOKAYE.

ble cable passing over said pulleys attached at one endto saidcounterweight and at the

